The present invention relates to the field of laser equipment, in particular to lamp pumped solid-state lasers used for applications in the medical and/or industrial sector, and to methods for easy and inexpensive replacement of said lamp.
Laser sources, in particular solid-state lasers, are optically pumped. Light at a given frequency is sent to the active material as a source of excitement. Where the active laser medium used is a crystal, the photons of said crystal, once excited, emit a laser beam at a defined wavelength.
The lamp pumped solid-state lasers commonly used in the medical and/or industrial sectors are, for example, the Alexandrite laser which emits at 755 nm+/−20%, the Nd:YAG which emits at 1064 nm+/−10%, or even at its harmonic wavelengths such as 355, 532, 1320, 1440. The Tullio laser emits between 1900 nm and 2000 nm+/−20%, the Holmium laser at 2100 nm+/−20%, the Er:Glass laser from 1540 to 1550 nm, the Er:YAG laser at 2940 nm, the Er, Cr:YSGG laser at about 2780 nm.
Generally, the light source is a lamp which is a glass tube sealed at the ends containing an inert gas under pressure, such as xenon, krypton, excimers, xenon bromide. The positive and negative cables connected to the capacitors which provide for storing and discharging to the lamp the energy required for the impulse, are connected to the terminals of electrodes at the ends of said tube. Depending on the operating conditions, said lamp has a limited life and, after a certain time, decreases in intensity. In addition to natural ageing, it may happen that a lamp fails suddenly, for example on account of breakage of the glass or otherwise.
To date, the replacement of the lamp requires the intervention of an experienced technician. The replacement of the lamp in the laser devices available to date involves the removal of part of the body, the opening of the optical bench, the detachment of the resonator from the hydraulic system after previously emptying out the cooling water therefrom, the disconnection of the electrical connections and then the removal and replacement of the lamp. This procedure involves the risk of soiling the mirrors on the side of the resonator, or the faces of the crystal. Also, there is a serious risk of breaking the lamp itself. Additionally, the laborious replacement of the lamp frequently entails a movement of the optical axis, with the consequent need to realign the optical bench. The drawbacks and costs related to replacing the lamp in laser instruments in use today are thus significant, in addition to the inevitable inconvenience of machine downtime.
By way of example, the full-time use of an Alexandrite laser entails the need for a monthly replacement of the lamp. The costs associated with the replacement of the lamp are therefore not negligible in the overall economy of use of the machine.
U.S. Pat. No. 4,313,092 describes a laser apparatus provided with an automated system for the replacement of the lamp. Said system comprises a mobile housing having a series of cavities, each of which contains a lamp. Said housing moves automatically so that at defined times a new lamp automatically reaches the operating position. The solution postpones the problem but does not resolve it, requiring operations of a certain complexity to replace the entire set of lamps available in the mobile housing cavity.
U.S. Pat. No. 5,012,481 describes a replacement block of a laser lamp. The replacement of the entire block facilitates the replacement operation but increases the cost given the need to replace the whole block and not just the lamp.
U.S. Pat. No. 4,644,550 discloses a lamp wherein the two end terminals are connected with cables.
U.S. Pat. No. 5,805,625 discloses a lamp with fittings that function as electrical connector to which cables are connected.
The need for a laser system in which lamp replacement can be performed rapidly even by an unskilled operator is deeply felt.